It is known that beta-hydroxyalkyl esters of polycarboxylic acids can be used as cross-linking components for the cure of non-acidic, hydroxyl-containing, resinous compounds in the presence of transesterification-promoting metal compounds as curing catalysts. See, for example, U.S. Pat. No. 4,332,711 issued June 1, 1982, and U.S. patent application Ser. No. 255,196, filed Apr. 20, 1981, and now U.S. Pat. No. 4,362,847. Such systems operate by transesterification of beta-hydroxyalkyl ester groups of the cross-linking component with hydroxyl groups of the resinous component, with elimination of a glycol.
A novel and convenient method for combining the two functions into the same molecule has now been discovered. These binders may be conveniently used in cathodic electrodeposition from an aqueous bath since the beta-hydroxyalkyl function will move at exactly the same rate as the resinous material in an electrical field.